


Hogwarts Au!

by minikeemoo



Category: Haikyuu!!, Harry Potter - J. K. Rowling
Genre: Alternate Universe - Boarding School, Alternate Universe - Harry Potter Setting, Alternate Universe - Hogwarts, Best Friends, Childhood Friends, F/M, Fluff, Fluff and Crack, Friendship/Love, Gryffindor, Hogwarts, Hufflepuff, M/M, Other, Quidditch, Ravenclaw, Slow Burn, Slytherin, they'll age up as the story progresses
Language: English
Status: Completed
Published: 2021-01-18
Updated: 2021-01-18
Packaged: 2021-03-16 02:01:22
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,028
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28823391
Author URL: https://archiveofourown.org/users/minikeemoo/pseuds/minikeemoo
Summary: Tsukishima and Yamaguchi are muggleborn first years attending The Hogwarts School of Witchcraft and Wizardry! High jinx is sure to ensue as this painfully long, not accurate to the book, slowburn continues.
Relationships: Shimizu Kiyoko/Tanaka Ryuunosuke, Tsukishima Kei & Yamaguchi Tadashi, Tsukishima Kei/Yamaguchi Tadashi
Comments: 2
Kudos: 22





	Hogwarts Au!

**Author's Note:**

> Please ignore grammatical errors! If I catch any, I'll fix them as soon as possible!  
> If you're here for romance, well buddy this is gonna encompass their entire Hogwarts experience, so you're in for the long haul, huh?
> 
> Also I know I said I was gonna continue my hunterpedia fic, but I'm feeling a bit of hxh burnout! I promise I'll continue this one though! I don't think I'm gonna burn out any time soon, and I really wanna fix the Harry Potter universe and make it better in order to silently spite jk rowling
> 
> ok one last thing- the indentations are all wonky on here and I can't fix them, so sorry! I don't know if they'll stay like that, but I promise I know how to indent papers lmao

Freshly fallen snow draped over the stair railings leading up to Tsukishima’s house. Yamaguchi approached cautiously, all too familiar with the pain that comes with falling down the icy steps. After slowly walking up to the door, Yamaguchi rang the doorbell and waited as padded footsteps came up from the other side and a satisfying click unlocked the door.  
“Hey, Tsukki!” Yamaguchi exclaimed as the cold made his warm breath visible against the snowy atmosphere.  
“What’s up? Why’d you come so early,” The blond boy tried and failed to rub the sleep from his eyes as he spoke.  
“I got a weird letter in the mail. I wanted to see if you got one too,” the freckled kid pulled out a letter from his poofy red snow coat as he continued, “It’s an acceptance letter to a weird, like, performance magic and fine arts school? The only issue is that I didn’t apply, so I wanted to see if I was the only one or not.”  
In response Tsukishima stepped outside, hugged himself, and walked swiftly over to his mailbox. His muscles tensed as he touched the cold metal and took out a small envelope with an elegant red wax seal.  
From across the yard he shouted “This what you’re looking for?”  
“Maybe, bring it over here.”  
Tsukishima swiftly scuttled back up to Yamaguchi and signaled for the small green headed boy to come inside with him. Both boys retreated upstairs to Tsukishima’s room, shut the door, and studied the curious envelopes.  
The letters were identical, save for the names they were addressed to. Both were yellowing, and stated “Hogwarts School of Witchcraft and Wizardry” at the top in a hand printed medieval font. Below stated some instructions, an introduction, a supply list, and a sign off from someone, presumably a teacher, named “Ittetsu Takeda.”  
Moments of silence turned into minutes until Tsukishima finally spoke. “Wow. Someone must’ve put a ton of work into this prank considering it didn’t work.” Turning to see a spaced out Yamaguchi, Tsukishima added, “Place your bets on the culprit now! I’m guessing it’s Jennifer. She’s always had it out for us,” he stated with a small grin.  
Still lost in thought, the small 11 year old agreed after a few seconds of silence in a monotone, lackluster voice.  
“Yama.”  
“Mmm?”  
“Do you honestly think this is real? Dude, we’re not little kids anymore.” Tsukki crossed his arms and tried his best to sound concerned despite being annoyed with his best friend’s immaturity.  
“I mean- I don’t know?” Yamaguchi stuttered out. His previous fascination with the letter morphed into intense anxiety at the notion that he was too babyish to understand school pranks. “I- I just think it’s a cool idea is all. Imagine being able to learn magic!”  
“I mean I guess, but I feel like society progressed passed the need for magic technology-wise.”  
“Easy to say that when your parents actually buy you a phone,” Yamaguchi stated with the angered expression of one who can’t make it past 1600 on “Like a Giraffe.”  
Noting the sour tone of his friend, Tsukishima began tossing and catching his phone both flamboyantly and repeatedly as he changed the subject. “Well, either way, these are trash. There’s no point in really keeping them.” With that, Tsukishima got up and tossed his letter in the trash. “Come on Yama, let’s go play some Mario Kart. We can make some hot chocolate later if we want, too.”  
Yamaguchi’s previously distorted face washed into one of excitement at the thought of beating Tsukishima as Bowser. Yamaguchi jumped up and exclaimed, “Yeah, ok Tsukki!” Yamaguchi’s strange letter sat forgotten in the corner of the room as the two young boys screamed and cheered over a Mario Kart tournament.

Tsukishima opened his eyes to the familiar sight of his dinosaur covered wall shelf and a snowy window. The air smelled cool and clean. Today was going to be a good day, he decided. Jumping out of bed, he put on a bathrobe and shuffled downstairs. As Tsukishima grew closer to the kitchen, the smell of food grew as well. Fried eggs on pesto covered toast and bacon awaited the eleven year old.  
His mother stood at the stove and turned around as her son appeared. “Hey, Kei! How’d you sleep?” She had on a bright smile and a robe matching her son.  
“It was nice. Speaking of nice, breakfast looks amazing! Thanks!”  
“Oh it’s no problem, dear.” She turned back to her eggs for a couple of minutes until an idea struck. “Hey, why don’t we watch House Hunters while eating breakfast? I saw this week has a budget of $50,000. Imagine!”  
As Tsukishima’s mother continued on her House Hunters rant, Tsukishima busied himself with lighting the fireplace. There’s only one issue with the task Tsukishima set for himself. There was a small envelope tucked neatly between two logs. Bending down, he picked the letter. Upon further inspection, it was identical to the one he discarded a couple days ago. Confusion draped itself over the young boy like fire around logs.  
“Hey, Mom?” He grabbed the letter and rushed over to the older woman. “Did you toss the letter I left in my trash in the fireplace? You can’t put paper in a gas fireplace,” he said with knitted brows.  
Tsukishima’s mother turned around once more to address her son. “No, Kei. I haven’t gone in your room since you made that big stink about me ‘going through your stuff.’ Also, I’m not dumb. Why would I do that?”  
“Yeah, I stand by that. I like having privacy.”  
“What do you have to hide?” The blond woman had a smug grin.  
“N-nothing. I just like knowing I can have privacy in general.”  
Well, regardless, no. I haven’t touched any of your stuff, that letter included.”  
A frown crept its way onto Tsukishima’s face. “Mm, alright.” Tsukishima left the letter on the counter and grabbed his breakfast. Both he and his mother settled down on their worn out old brown couch in the living room after turning on the new envelopeless fireplace and setting up the next episode of House Hunters. A sardonic, taunting yell erupted from each side of the couch as the mother and son made fun of idiotic home owners. Once again, the letter remained tossed aside and forgotten.

A shout from his mother shocked Tsukishima from his concentrated daze. After he finished hanging out with his mother, the young boy went up to his room to work on his and Yamaguchi’s Minecraft world in an attempt to impress his one and only friend with a huge Western European style castle. Reluctantly, he got up and went downstairs to see what she needed.  
“What’s up, Mom?” He asked, light confusion embedded in his tone.  
His mother looked at him with the same confused expression as her son. “Yamaguchi’s on the phone, Dear. He said he needs to tell you something important.” Tsukishima grabbed the phone greedily and ran back to his room, violently shutting the door behind him.  
Without giving Yamaguchi the chance to explain himself, Tsukishima questioned, “Why didn’t you call my cell if this was important?”  
“Pride. If I don’t get a phone, I’ll act like you don’t have one, too. It’s like an even playing field.”  
“Blame your parents, not me.”  
Sorry Tsukki, but nah.”  
“Whatever. What’d you need anyway?”  
Tsukishima could practically see Yamaguchi’s expression with how eccentrically the shorter friend gasped over the speaker. “I got a new letter!”  
Annoyance replaced Tsukishma’s previous bewilderment. “Yeah, it’s a dumb prank, Yama. That’s the whole point.” He faltered before adding, more quietly this time, “I got another one, too.”  
“No! This one’s different!”  
A few seconds later, Tsukishima heard Yamaguchi’s mother tiredly yell, “Quiet down, Tadashi!”  
Sorry, Ma!” He turned his attention back to the blond. “Listen- this one was in my secret spot.” He paused and waited for Tsukishima to egg him on. He didn’t. Despite getting no reaction, Yamaguchi continued, “Okay, so, it’s a hidden spot where I keep my journal, and it’s such a huge secret that not even you knew about it until now. But the letter was just tucked neatly in there. The hidden spot’s hidden underneath a loose floorboard under one of the bed legs. It’s completely invisible, so no one would be able to find it without spending a lot of time looking.”  
“Wait, you have a diary?”  
“Shut up. It's a journal.”  
“Yeah, okay Greg Heffley.”  
“This is why I’m your only friend.”  
“ Yeah, well, your diary’s the reason I’m your only friend.”  
Yamaguchi grimaced. “Touché.”  
“Wait.”  
“What.”  
“You checked under the floorboards because you originally wanted to write in the diary and was instead met with the letter, right? What were you going to write in it?”  
Tsukishima was met with radio silence.  
Switching gears again, Tsukishima asked, “Fine. Well, Anyway, what’s that supposed to mean? Do you think you have a stalker or something?” Even though he kept a calm demeanor, Tsukishima knew he’d start balling on the spot if he and Yamaguchi had a stalker.  
“No, it’s magic,” Yamaguchi paused, “maybe."  
“I’m hanging up.”  
Tsukishima pulled the phone away from his ear and repositioned his grip so he could end the call, when he heard a muffled yell of, “Wait! don’t hang up,” erupt from his hand.  
He put the phone back up to his ear. “Fine, but don’t shout anymore, and stop spouting annoying nonsense. I don’t want this to turn into another 'fart ghost fiasco'.”  
Yamaguchi chuckled uncomfortably. “First of all, that ghost was real," he sighed and continued, “but no, it won’t be a fiasco. Probably.” He didn’t sound very convincing.  
“Okay! So anyway, I think that Hogwarts school sent the letters magically to get my attention because I threw out the last one.”  
The blond child scoffed. “What kind of school sends repetitive admission letters to students who never applied in the first place?”  
Yamaguchi sounded as though not even he believed himself as he replied, “a magic one?”  
“You’ve lost me. Even if it’s a magic school, and all of this is real, that’s not how proper schools function. What are they going to do if we don’t respond? Kidnap us?”  
Tsukishima could just about feel Yamaguchi coil in on himself and grimace, “Maybe we should write back? We could always send a formal decline.”  
Tsukishima’s face contorted into a grin far too wicked for an 11 year old. “Okay, now it’s time for you to humor me.”  
“Uh... Okay.”  
The grin only grew the longer he had time to create a plan. “Let’s write back accepting, ask for the school address, and then bust the pranksters with the police.”  
“And what if the school’s real?”  
No. I said you have to humor me now. Come over here. I’ll make some sandwiches and hot chocolate for us while we brainstorm how to properly address this 'school.' He made parentheses around "school" with his hands that were invisible to his freckled friend.  
A half-content, half-terrified hum from Yamaguchi set the plans in stone as both boys hung up to get ready.

Yamaguchi carefully maneuvered up the icy steps the same way he always did. The blond was waiting at the door and quickly pulled Yamaguchi inside. The sandwiches were already toasted and the hot chocolate already marshmallowed. The meals sat waiting on Tsukishima’s bedroom desk, leaving some library books and mint-edition boxed dinosaur figurines pushed aside. Both boys ate their meals while cuddled up on Tsukishima’s bed and watching “Dan and Phil Play CHRISTMAS SHOPPER SIMULATOR 2.”  
Once finished with their sandwiches, Tsukishima left his room to go fetch materials for their letters. Before he came back, he stopped by his brother's room to check that Akiteru was still at volleyball practice. Tsukishima worried that explaining what he and Yamaguchi were doing would’ve been both embarrassing and a big time consuming hassle.  
Now confident that Akiteru wasn’t home, he threw open his door and tossed the supplies on his startled friend’s lap.  
The evil smirk made a reappearance, this time corrupting the tall child’s eyes, “Alright! Let’s get started!”


End file.
